Variation in the parasitic bee mite Varroa jacobsoni Oud.

Denis L. Anderson

CSIRO Entomology, G.P.O. Box 1700, Canberra, ACT 2601, Australia

Abstract:

Initial searches found little evidence of genotypic or phenotypic variance in the parasitic bee mite
Varroa jacobsoni, despite numerous reports of significant variation in the mite's reproductive
behaviour on its adopted host Apis mellifera. However, in a recent search that employed DNA
sequencing techniques and large numbers of V. jacobsoni collected from the mites' native host
A. cerana throughout Asia, a remarkable amount of genetic variation was observed. Subsequent
analysis of this variation, coupled with follow-up morphological and ecology-based studies, showed that
V. jacobsoni was a species complex. Other work carried out as part of that study also showed that
only two out of 18 genetically different mites within the complex have switched host to A. mellifera
and become a pest of this bee worldwide. These two mites are not V. jacobsoni as has been assumed,
but they belong to a group of mites that naturally infest specific populations of A. cerana on
mainland Asia. These mites will soon be renamed as a new species. This and other reports of variation in
V. jacobsoni are reviewed and discussed.